To prevent you from
inadvertently loading mod_perl 1.0
modules, mod_perl 2.0 Perl modules are installed into dedicated
directories under Apache2/. The
Apache2 module prepends the locations of the
mod_perl 2.0 libraries to @INC:
@INC is the same as the core
@INC, but with Apache2/
prepended. This module has to be loaded just after mod_perl has been
enabled. This can be accomplished with:

use Apache2 ( );

in the startup file. If you don't use a startup
file, you can add:

PerlModule Apache2

to httpd.conf, due to the order in which the
PerlRequire and PerlModule
directives are processed.